Shield for use in the production of radioscopes or radiographs



Aug. 9,1927. 1,638,683

M. DEMARCHI SHIELD FORUSE IN THE PRODUCTION 0F RADIOSGOPES OR RADIOGRAPHS Filed Jan. 12. 1926 2 Sheets-Sheet 1 gnmtov M /a/a DEM/IECH/ Guam.

I M DEMARCHI SHIELD FOR USE IN THE PRODUCTION OF RADIOSCOPES 0 R RADIO GRAPH S Filed Jan. 12, 1926 2 Sheets-Sheet 2 I F/ I :V

l l I I I I I I I II I INVENTOR MAE/0' DEM/I 2cm ATTQRNEY Patented Aug. 9, 11927.

. A l were V sn-rnnn :FOR"U'$E 1N THE rnonuorrrolv. or aenztoseorns on nAnrojGRAPHs;

; fipplicationfilectlanuary 12;, 1a2e,'seria11v; s0,a2c, nai'nnai Januar -17,1925.

invention has for itsCobj'ect an ap-l f paratus adapted to avoid the difl usion; of secondary. rays and their dangerouseffects on radiographic plates, and some drawbacks 5 in connection therewith, as will appear.

Several devices have. previously beenproposed to' filter'the radiations emanating from the anti-cathode, warm-110w the direct or primary radiations: only to reach the plate.

Generallly'suchfilters comprise sheet metal members or laminae fixed to'a frame with their faces radial in respect ofthe'source of radiations, and at; a comparatively short distance from each other so as to intercept the secondaryradiations, which are oblique to the radial directionabove-referred to. The shields of thiskind heretofore known perform either a translatory mctionor a rotatory motion about'an axis at right angles to the shield.- In=eit-her case the 'following disadvantages are observed; (1;)', a series of linesor areticu'lation formed by the shadows of'thesingle-fixed eleinents (laminae) pro'- 'jected over the late, and 2)= a; consider:

abled ifierence of intensity; between the radiationsreachingthe periphery of the plate and those reaching the central zone thereof, where the motion 'is' comparatively slow and the plate is nearer to the source of radia tions.;

7 According to "invention Ielimina-te the drawbacks above 'mentioned, by providing one or more series of vibratory laminae or blades of X-ray opaque material. arranged in a rotatable circular frame, parallel to one.

or more diameters thereof, each blade being fixed at one end to theframe and free to oscillate at its opposite end, the free ends substantially lying on a diameter of the tion of the blades. 7

In the annexed drawing there is diagram matically shown'an embodiment of my invention, Fig. 1 being a plan, while; Fig. 2 .is a cross sectional view, Fig; 3 is a partial sectional view on the line IIIIII- Fig. 1, and Fig. 4 is a partial sectional view on the line IVIV. Figs. 5 and6 are side views by way of example of theend portionsof V two pairs of contiguous blades.

' Figure 7 is a plan view of an alternativev embodiment-of my invention, and I Figure 8 is a cross section of the same on line VIII VIII. q The apparatus according to my invention comprises a circular frame which I assume frame at right angles to the common direcv to be I horizontal, :fo'r ieiiplicative only, though practically: it may take any positionsldesired. The frame consistsofva pair of. superposed rings 2,'-3 ,-secured t togethen and havingsuitably fixed thereto a numbero'f' blades or lamineetparallel? toa diameter thereof. As shownjbyF-ig's; 1, 5] I and 6,; each 0f the bladesltqcomprises two halves, 4 andAP, respectively fixed at their 'out'er-endsto the frame and fre'e for vibrating at. their inner" ends, which preferably overlap each other alternatively,"from right tained in planes passing," the source of radiat ons.

will cause a vibration of th'e biades] A: shadow'eife'ct will jthus--be= observed on the plate say 'a;'sequence of nstantaneous' interruptions; of'the radiations "reachingthe plate, said sequence being in" .everypoint inverselyproportionalto thes' peed'v of the-point of theshieldgand at'thesainetifneleach blade-=5 raml'n'atically 1 and [5,; 1n

.to' left, andfivice-versau The blades, are'cone i j as usualg'through 'By causing"the.frame to-irotate aboutits a centre by 'any'means- (say forfexaniple,jbyi 1 means of a: toothed pinion-meshing iwith a rack onythe periphery of-the fra1'n'e)', the 'blad'esjwill vibrate-as fidis prevented from imprinting any constant I shadows on the plate, so that the formation of. Q

circles or any other geometricalfigure from the successive shadows .of the blades will be avoided, the shadows due to one. half of the blades being practicallyeliminated by those due to the other half thereof.

My invention also provides .aparticular means for securing the bladesto the frame.

Each blade-(see Figs. .3 and ,4). is provided with a pivot or gudgeon 5, engaging a' V-'shapedgroove 6 in the lower ring 3. Op

posite each groove the ring. 2 l1as a pressure screw 7 adapted to lock the gudgeon 5. This arrangement allows of an easy'adjustment;

of the transverse inclination of the blades,

shield.

annexed drawing comprises a series of vibratory blades only,'but itis obvious that a and has the advantage that such inclination may be varied at will, according to the distance of the source of radiations from the more effective interception of the secondary fradiations vvill be obtained. by arranging blades divided in two. halves 4 and 4 a rlower circular frame provided-With like blades 4? and-4 the two frames being so arranged over each other that the longer parallelsides ofthe upper series of blades Will Jbei at right angles to the lilreisidesof-the lovver-se'riesof blades.

OVer 'each otherin a circular frame two series of blades, having respectively their; p p

radioscopes or radlographs, compr1s1ng a c1rlonger sides parallel to a pair of diameters at right angles to each other."

"Figures? and 8 diagrammatically show,

for the sake of example,such a modified construction. of, a vdouble 'Rontgen-rays shield. 8 is an upper circular frame providedwith 9-is My invention is notobvio u'sly-limited to any particular shape of frame, nor to any particular means for imparting the rotatory motion thereto, and may be .perfor'medwith considerable changes in construction ascon'ipareda it-hthe embodiment; shown fol-explanatorypurposes only. y a

"What I claim, as my invention is: 1 E

;1., A -shield for .usei the productionof 7 radroscjopes or radiographs, compr sing a circular frame, strip-shaped blades of LX-ray opaque materialrmounted in said frame with i'theirlonger sides parallel to one diameter thereof, each blade being formed in twohalves, and each half being. fixed at one end 'to'the frame, and being free to vibrate at vthe opposite-end upon a motion being im-' partedto the frame. a

,2. A shield for use in the production a .radioscopes orradiographs, comprising a rotatable circular frame, a number of stripshaped bladesof X-ray opaque material each substantially divided in two halves, each half blade being fixedat one end to the-frame and I means to impart rotation to the frame.

3. A shield for use in the production of cular frame, a number of blades of X-ray opaque material parallel to a diameter thereof, means for adjustably securing One. end of part rotation thereto, said blades beingfree .to .vibrate at their 'opposite ends and terminating short'of each other substantially upon adiameter at right anglesto thefirst named diameter-of the frame.

4:.f-Inshields of the kind described a ciicular frame, -a-zseries of blades of X-ray opaque materialsparallel to a diameter thereof, and means for securing the blades: to the frame, comprisin an upper and a lower supe1'poseclring,'V-s iaped grooves in the upper V. V face of the lower ring, said groove's being parallelgto a diameter-of the'frame, a gudgeon provided at one end ofeach-lbladeand adapted to engage the said V-shape'd grooves,

Ashieldfor use inlthe lproduction of radioscopes or radiographs,comprising a cir- 'culai' frame, a;ser1es 'Qf bladesjof','X-ray opaque. material arrangedjparallel to-onje .each blade to saidframe, and means to im diameter thereof and adapted to vibrate Eat: oneen'd, and a secondseriesof' bladesalso' adapted to vibrate, arranged underneath the I? said first named series, and parallel ;;to,- an other diameter of; the frame at I right; angles to thesaid first named diameter In Witness whereof, I have hereunto signed i my name. 7

s V MARIO DEMAROHI. 

